The analysis of natural language trait names and questionnaire scales has suggested that the 5 factors of Neuroticism, Extraversion, Openness, Agreeableness, and Conscientiousness constitute an adequate taxonomy of personality. An alternative approach to comprehensive personality assessment based on clinical judgments is given by the California Q -Set (J. Block, 1961). When self- Q -sorts from 403 adults (aged 28-84 yrs) were factored, the 5 factors closely resembled those found in adjectives and showed convergent and discriminant validity against self-reports and peer- and spouse-ratings. Results were replicated when interviewer Q -sort ratings were examined for a subset of Ss. Findings support the comprehensiveness of the 5-factor model.